Soldering irons



J. F. THOMASL soLnERING IRoNs Oct. 3, 1961 2 Sheets-Sheet 2 Filed Jan.14, 1960 Q9 VIII/ FIG.

FIG. I5

JOHN E THOMAS NVENTOR. n nimm 7,7- roes/EY f use does not change theorifice size. i f

` This invention relates to magazinefed soldering irons,

United States Pafenff) andmore particularly to working tips `for suchsoldering i irons. f

.In soldering` irons of the class described, it is conventional to feedsolid solder from a magazine into the orifice of a working tip whereinthefsolder is melted. Further feeding of solid solder forcesmoltensolder in? theorice outV upon the pieces to be soldered whilereplcnishing the supplyof molten solder in the tip. One of thediiculties encountered with soldering irons of the class described is othe retention of moltenk solderV in the vorifice `when the working endofthe tip is downwardly directed; That is, o under the influence ofgravity, molten solderinlthe' orifice.,

simplyoruns out. This dillculty can be alleviated some-lnk fwhatbyinserting in the orifice of the tip, a` woven may yterial `which is notwetted by solder. The surface tension of thevmolten solder intheinterstices of the mateyrial can thus provide a force which will supportthe column` of molten solder against the force thereon due to gravity.``However, this solutionrequires the insertion of 'a specialV wovenelement into thetip and thus addsto the complexity and cost of amagazine fed soldering iron.

Much, effort has been expended by those skilled in the i art to providea soldering iron of the class described `wherein the provision of anextra woven element in the orice of the tip is not necessary to preventmolten sol- .der therein from running out when the working end of thetip is downwardly directed. ilt is therefore an object p of thisinvention to provide a tip vfor a soldering iron of the class describedwherein 'a column of molten solder is u supported against the force dueto gravity without obstructing the orifice in the tip.

Afurther diiculty with soldering ironsofthe class described can bebetter appreciated by considering the fact that heat from the tip isrconducted through the molten `solder to the still solid solder in themagazine. Obviousl ly, where the iron is in constant use over a periodof time, the heat so conducted willmelt the solder in the magazineunless an operator periodically shuts olf the iron. However, such ahaphazard control is highly undesirable, particularly when duction work.p h

Much effort has been expended by those skilled in the art to provide aAsoldering iron of the class described which does not have to be shut oin order to prevent heatfrom the molten solder frommelting the solder inthe magazine, but so far as is known, the problems described aboveremain unsolved. It is therefore a further object of this invention toprovide a soldering iron of i the class described in which neither heatfrom the tip nor heat from the molten solder can cause melting 'solidsolder in the magazine. V

Those skilled in the art recognize that molten solder on passing over atip will erode the latter. In soldering irons of the class describedwherein the tip Yis provided `with an orifice, it is believed apparentthat after an extended period of use, the orifice will become enlarged.Thus, if it is necessary to maintain the orifice constant, the tip wouldhave to be replaced after a period of prolonged use.

Much effort has been expended by those the iron is being used in pro-Ice. f

As a feature ofthis invention whereby theobiects thereof are achieved,the surface ofthe tip delining the orifice thereinfis made so as to bewetted by molten solder', and the transverse cross-section of theorifice is ad- Yjusted until a column of molten solder of any desiredspacing being determined by a meanswhich is not eroded by molten solder.The separable parts of the tip are ret siliently urged toward each otherso that erosion ofthe tip has no electon the desired spacing. f As afeature of this invention whereby heat from 'the tip and from the moltensolder are prevented from melting solid'solderin the magazine of theksoldering iron, a resilient element which has a low heat transfercoefficient,

and which is not wetted :by moltenfsolder is placed between the'tip`andthe magazine. The solid solder is stii enough Vto push the element out`of its path and gain an kentrance to the oricein thetip. However,theelement will resiliently close when the solder therein melts. Thishas the desired eiect of thermally insulating the solid solder from themolten solder.

The more important features of this invention have thus been outlinedrather broadly in order that the detaileddescription thereof thatfollows may be better understood, and in order that the contribution tothe art may be better appreciated. There are, of course, additionalfeatures yof the invention that will be described hereinafter and whichwill also form the subject ofthe claims` FIGURE 2 isk a Vsection takenon the line 2-2 of FIG- Y URE 1.

FIGURE 3 is a sectional view similar to FIGURE l showing how solidsolder from the magazine can push aside the thermal cut-off device. oFIGURE 4 is a sectional view similar to FIGURE l but showing how thethermal cut-ott closes when the solder in the tip melts and thusthermally insulates the solid solder from the molten solder.

FIGURE `5 'is a sectional view showing another embodiment of thermalcut-olf.y

FIGURE 6 is a perspective view of another embodiment of capillary tip.

FIGURE `7 is a sectional view showing a split capillary tip and one formkof erosion compensating means.

FIGURE k8` is a'section taken on the line 8 8 of FIGURE 7.

esV

skilled in the art to provide a tip whose orifice does notr d becomeenlarged rafter prolonged use, but so far as is known, the vproblemremains unsolved. It is therefore a still further object of thisinvention to provide a tip for a sclderingiron of the class described inwhich constant VVFIGURE 9 is a sectional view showing a split capillarytip vand another form of erosion compensating means.

FIGURE l0 is a view taken on the line 10-,10 of FIGURE 9.

FIGURE 11 is a rear the invention. o

FIGURE 12 is a sectional view taken along the line view of anotherembodiment of Y 12-12`0f FIGURE 11.

u fPatented Oct. 3,1961

' ly'actuated, solid solder will eventually till ,ELGURE 13 is afrontview of the embodiment of f-ironfrnade in accordance with the inventionis designated @generally at 10.

Iron 1G has-handle 11 containing a magazine (not shown) for solid solderV12 which is fed ff through orice 13. Feeder 15, slideably mounted inkslot --1,4,-isvv aotuatable by t-he iingerof Van operator to force',solid solder 12 through orifice 13 into cylindrical body '16'which ismounted in handle 11 in recess 17. Body 16 has oriiice 18 aligned withorifice 13 for forming repassage through which solid solder is fed totip 19.

Cover 2@ surrounds body 16 and connects tip 19 to handle A11. rlip 19has orifice 21 which is aligned with ori'lice -1,3 in body 16. In thismanner, selective actuation'of feeder 15 causes solid solder to be drawnfrom the magaf zine and fed into the tip. Tip 20 is also provided withresistance heating elements 22 which helically surround oriiicevZl andprovide a source of heat serving to keep :the tip at a workingtemperature at which solder incrice 21 is maintained in a molten state.

yItshould be apparent that if the heat from elements 22 were conductedto body l5, the solid solder in orifice =.13 would soon be reduced to amolten state. It is also l. apparent that heat from the molten solder intip i9 will *be conducted therethrough to the solid solder causingprogressive melting of the solid solder until the magazine is reached.To prevent this from occurring, thermal cutol device 23 is interposedbetween body 16 and tip 19. Thermal cutoff device 23 is a disc ofresilient material having a relatively lou.I heat transfer coefficientatthe Tworking temperature of the t-ip. Such a material is siliconerubber. Disc 24 is held to body 16 by cap 25. Thecenter of disc 24' ispunctured at 26 to form a fissure `aligned Iwith apertures v18 and 21.Such fissuresmay fbe irl-the form of a cross, the purpose being for thedisc to be resiliently deformed by the solid solder when feeder 15 isactuated. in such case, the fissure is enlarged by thesolder as shownbest in FiGURE 3 to effect its passage from the body to the tip. Asfeeder 1S is successiveaperture 2l, to the entire length of .tip 19.Heat from elements 22 will eventually melt the solder in tip 19. Themolten solder is, of course, much softer than the solid solder :withinvdisc 2d. When the solder in disc 24 eventually melts, the resilientnature of the material of disc 24 causes :the fissure to close as isshown in FlGURE 4. Ifn this manner, disc 24 serves to thermally insulatethe solid l solder in body 16 from the molten solder in tip 19.

To thermally isolate body 15 from tip 19, discs 27 of glass ber or likematerial are positioned between'cap 25' and the tip. Such discs may berigid, in which case a hole of substantially the same diameter as thesolid Ysolder is provided in the center of the discs. On the other hand,the discs may be laminated sheem, in which case a slit provided in thecenter of the discs is sutlicient to permit passage of soldertherethrough as shown 'in It has been found that discs 27 alone maysometimes serve as a thermal cut-off without the necessity forrubberdisc 24. In such case, body 16 should be made from 'a Vmaterial havingVa high heat transfer coefcient. in operation, the solid solder in body16 is connected vto the molten solder in tip i9 by the solder containedwithin-the holes in discs 27. The solder in the holes under- -goes achange of state from molten to solid as the heat from the molten solderis quickly conducted through body f-16 whichl actsas a heat sink,absorbing a great deal of heat without reaching a temperature sufficientto melt athes'older therein. The remainder ofthe soldering iron ofcourse cooperates with body16-,'in.thisregard. As a andere@ t result,Athere isno mechanical break in the continuity of Yor the Ylike is,inserted in slot 31 in body 16'. The forward face of` strip .30 iscovered with a thermal insulation 32.

Strip has a normal position shown in FIGURE 5.

`However, actuation of the feeder causes strip 30 to be deflected outofthe path of solid solder 12 to another position such- ,that the solidsolder can enter -aperturell in'tip 19. -Recalling that strip 30 isspringy, it will be yevidentthat-.thev strip will be urged toward its`normal position. 'solder =in Aoriiice Howeven when heatY from tip.19melts ,the 21 and the solder cont-acting strip30 willgrrnove .to itsnormal position where it will thermally Vinsulate the solid solder inbo-dy 16 from molten solder in -oriiice V21.

Referringnow to FIGURE 4, where the molten solder N/is-designated at12', it is believed evident that the molten 25.

solder will be Vreadilyavailable where an operatormust rotate` iron 10Vto a vertical position with the Working -end 19' of tipr19 being abovehandle 11. However, were the operatorto-rotate iron 10- until workingend 19' vis downwardly directed, Asolder. 12' would 4be drained from theY,tip byr gravitationalv force exerted on the column of solder unlessprovision were made for the contrary. Provision is made bythe meansshown best in FlGURE 2. Tip 19 iskformed of two parts: inner cylindricalmember 40 and outer cylindricalmember 41. One face of each member abutsdiscs 27, while the other face of each member con- :f stitutesv theworking end 19'. Heater elements 22 are contained in member 41 which maybe of aluminum or like metaLuwhiCh has good thermal conductivity and` isnot wetted byrnolten solder. Member 40 contains the orificeV21therethrough, and may be of copper or like metal that is wetted bymolten solder. Slot 42 in member 40 connects the exterior surfacethereof with orice 21. `The purpose of this construction is two-fold:(l) a path for the flux is provided by the non-wetted portion of memberdi, which path extends from face to face, and (2) capillaryforces serveto maintain the column of molten solder in orifice 21 againstgravitational forces. This latter factor` arises because the surface ofmember 40 which defines orilice 21 is wetted by molten solder. By asuitable choic-eof orifice diameter, a column of molten solder of anydesired height can be maintained. Obviously, the column Yheightshouldrat least equal the length ofthe tip from face to face. Thus, ifthe iron shown in FlGURE v4 were rotated until working end 19 weredownwardly directed, the ysurface tension of molten solder 12 ineooperation with thewettedfsurface defining orifice 21 will `maintainercolumn. of molten solder at least the length ofthe tip, and no solderwill be lost.

AV modilication of the tip previously described is'shown nt- 501m FIGURE6. Tip 50 is cylindrical to t Within cover Ztl, and has an axiallyextending orifice 51. Orifice 51 is of uniform diameter. However, sincetip Sti is of a ...material thatis wetted by molten solder, a portion 52of vvthe-surface-dening.the orifice is coated with a substance which .isnot wetted'vby .molten solder. Surface 53 forms awetted surface andallows the surface tension of the ymolten solderin orice 51 to support'the solder entirely within thecrice. A Surface 52 extends the length oftip 50 and forms a path for the uz.

Y Itshouldnow be apparent. that it is important tomain- -tain thespacing of the wetted walls in the tips above de- -scribedin order to beassured that surface tension'will hold themolten solder in the tiporice. isolderero'des theorice and tends to enlargethe same However,

after a period of use. If this were allowed to occurathe satisfactoryconditiongthe inventionshown in FIGURE 7 can used. InFIGURE .7,7tip` 60is made'separate and .of a material wetted bysolder. "Iip 60 hasopposing surfaces` 61 Tin lorder to 'achieve the labove describedcapillaryactionJ '.Tipf60 is housed infcover 20 fromwhich "protrude aseries of aligned `bosses, 62; Springs63 en- `gaged over`bosses 62 andbosses-64 resiliently -urgefsur yfaces ltoward each other. yThe desiredspacingrbetw'een such surfaces is achieved by'lugs 65 on `cover 20 whichprotrude between'the surfaces; Since lugs 65 arev not wetted by solderthey are not eroded. Erosion of surfaces .61 is therefore compensated bysprings 64 moving i `FIGURE9y is a modification ,of the invention shown'in `FIGURE 7.: "Tip 70 is also in `two parts, andfhas surfaces 71 inroppositiomwhich' surfaces are wetted Aby moltemsolder." :Theoutsidesurfaces of vthe parts of, tip ,70 arecurvedv asfsecn inFIGURE 10.Surrounding tip 170 helical spring 72- Insertion of tip 70 with spring72 places the spring in tension whereby surfaces '71 are urged together.l Ends 73 and 74 on spring 72are1bent inward- -lybetw'een surfaces V7lto form stopsv to define the mum spacing between the surfaces;r Cover20" encloses spring 72. In operation, as surfaces 71 are eroded byImolten'solder, spring 72aresiliently urges the surfaces together ontoends 73 and 74. f y Y Another embodiment of the invention is showninFIG- URESllthrough 14, and is particularly suitable for desoldering aswell'as` soldering, as will be more evident yfromthe followingdescription. The principle Yinvolved includesA the use ofcapillaryaction tosupport a column of molten solder against thepull of gravityand so permit an operator to orient theironin any attitude without themolten solder running out. The capillary action arises in the-embodimentshown in FIGURES 1'1 through 14 because` of the `provision of opposingwettable surfaces 4whosespacing is such as to cause the surface tensionin the'inolten solder to lproduce `the neededsupport. In addition, thesurfaces are made selectively movable relative` Ito -each other; As: aresult', molten solder between the surfaces is forced out upon selectiverelative movemerrtof, thesurfaces toward each other. While this is .Aadvantageous when it desired to4 depositsoldcron `a work piece, it alsoenables this embodiment of the invention to serveas'an etfnfcientde-soldering tool.

ff-In `connection with,k the latter use, jit is believed" evi- ,dentthat when the surfaces are spaced and no solder lis s therebetween, thetip canbeused to first melt the solder VronA a connection. The Vmoltensolder is thendrawn by capillaryi action (away: from` the connection 1and n up betweenlthe surfaceaflhis can beaccomplished regardless of theattitude ofthe tipvand the work piece, as forexamplerwhen the tipisvertically `below the connection desiredto be de-s'oldered'..theconnection is devsoldered, the inoltenA solder is 'removed frombetween the e'ach other.v n' f p @Referring now. toFIGURE 11,tip 80 isshown with a cylindrical bodym 81 having an axial orifice 82l throughwhich solderis adapted to pass. Attached lto one end of u body. 81isrectangular plate 83, which hassurface 84 into ...which orifice ,.82opens. Extending forwardly from sur- -face 84 are guide klugs85;.nea.r.the top corners so that ..surface88 of yplate f8.6 is guidedfor movement relative yto lsurfaceftori,plate 83. 1 f l Y s l l Toprevent separation ,ofplate 83 from plate v86, cover 89 isused..`C0.ver89 has a fportion 90 which encircles .rbody81and1is `thussecurelyr4 retained thereto. Portion 9 1 ,ofcov'erl 89is U-shaped andengages plates 83 and 86 to limitthe -maximumspazingbetween surfaces 84and surfaces ,by-selectively moving the surfaces relative to 88. In thismanner, plate' 86 `is connected tojplate 83,.

and plate 86 can be moved from a position whcresit is spaced fromportion91` and surface 88 abuts to aV position where it abuts portion 91 andsurface 88 is atits maximum Vdistancefrom surface 84.

To control theL spacingbetween surfaces 84 and88,wpull rods" 92 arerigidly secured to plate 86 and slideably pass through holes 93 in plate83. Spring 94 has its ends resting against plates 83 and 86 respectivelyand ythus biases plate 86 away fromplate 83. Selective pullinglof rodsy92 compresses spring 94 and decreases the spacing between faces 84 and88. Release of rods 92y causes spring 94v to move plate 86 to theposition shown in FIGURE 14. Orifice v82and` surfaces 84 and 88 arewettable by molten solder. vWhen heat is applied to tip 80 by heaterelements (not shown), and work end 95 is against a soldered connection,the heatwill melt the solder. Capillary action Y draws the molten solderfrom the connection upl between sov surfaces 84 and788,` regardless ofthe lattitude of end 95. When the connection isdesoldered, theoperatorremoves the' tip from the connection. Pulling rods 92 causesthe solderbetween surfaces 84 and 88 to be squeezed out from tion forde-soldering'another connection."

To increase the flexibility of tip 80 and permit the same therebetween.,Release of rodsV 92 placesthe tip in condi- "to be used as a solderingas well asa. d`e-sold`ering device,

check valve 95 maybe insertedinto 0rifice'82` where it connects withsurface 84.- In this manner, molten solder between surfaces 84 and 88 isnot forced back into Orifice j 82 when rods 92 are pulled. However, anoperator` may still feed molten solderfrom a magazine to end 95k in' thesame manner as'waspreviously described.

The tip shown in FIGURES 11 through 14/ can termed linear in that workend 95 defines aV line.'V

However, `it is obvious that the length of theline is unimportant so foras the soldering and de-soldering features are concerned. Thus, end 95could be a point or could becurved, depending upon the particular jobapplicatiorx.' It is first emphasized that when used as a soldering tip,end 95 would first'lieat the connection, and then the operator couldeither pull rod 92 to squeeze the solder onto the connection, or feedadditional solder through orifice 82 without changing the spacing oftheopposing surfaces. When used as ade-soldering tip, the operation is asdescribed previously. Y

f Where the connection desired to be de-soldered (or soldered) iscircular, as for example, multiple connections on a tube socket, theembodiment of FIGURE 15 can be used. Here, tip 80' is similar .to' tip80 except that molten solder moves radially toward or away from thecenter of circular surfaces 84' vfandf88'. Operation of tip 80 issimilar' to that of tip^80 in that the opposing surfaces are urged apartby spring 94 but can bedrawntogether by pulling rod 92 rigidly connectedto plate 86' and slideable through plate 83.. Of course the shape ofplates 84' and 86"could be whatever shape is necessary to accomplish thedesired end, andcould be square, rectangular, or triangular as well ascircular.

Sometimes the nature of the connection is such that the connectiondesired is circular and lies in a plane. yAn

` example of this would be Aa can top.` In such case, tip 80" can beused. Tip 80 is similarrtok tip 80 except that movableplate 86 is madewith its upper surfacewettable by moltenV solder 4and its lower surfacenot wettable.

comprising: a body haaving an orifice through which Again capillary actionfretains molten solder'in therannular region between plate'86" andplate 83", and inthe region between wetted surfaces 84 and 88".`Movernent of plate 86"y toward 83 until edge 97 is even with the bottomof plate 86, vwill deposit ther correctjamount of solder on ,theconnection.

What is claimed is: 1. A self-.feeding soldering iron of the classdescribed solid solder is adapted .to pass; a tip having an orifice ytherein aligned with the Orifice in said body; actuatable {fcedenmeansfor selectively feeding the solid solder through thel orificeinfthefbody into the orifice in the-tip,

adapted to` bezheatedato: a' working. temperature at; which the soldercontained in thextiporiee 'is maintained in a molten` stator-andvheatinsulationV means inter- Lposed between said body and said tip,isaidLilastf named =^means including means responsive-ntoactuation.ofi said j--feederrneans for eecting entry oflsolidlsolder fromrsaid "body intosaid tip and to deactuation ofsaidffeedermeans ylfordisconnecting moltensolder 'in-:the tipf` from f solid 2 solder in the body, wherebyAmelting-ofsolid solderin the "latteris prevented.

2. A self-feeding soldering ironof thefclassdescribed Lcomprising: abody having 'anforiiice'v through which #solder is adapted to pass; atip having.:an:orice.therein waligned lwith the orifice insaidbodyyaotuatable Afeeder f means for selectively feedingthe-solidsolder through the ffcomprising: a body havinganfforicethrough which'f'solder is adapted 'to pass; a tip having-1an:orice'fthereinA:'aiigned with the oriiice invsaid body; vJ-.a'ctuatable:feeder imeansfor ,selectively feeding the solid` solder-through'the -'oritice in thebody into the forice `in theztip; meansin said tip for heating the. sametof afworldng temperaturev at which solder contained in thetip-oriiceiis maintained rin amolten state; and thermal cut-olf meansinterposed Abetween the body and the tip, said-thermal cut-od meanshaving an open position for effecting:interconnection-be- "twecn theorifice in the tip and the oriiicein the body and aclosed position fordisconnecting the apertures, said `vthermal cut-off being movabletoclosed position upon melting of the solder in the tip whereby? themolten solder t' in thetip is mechanically separated from thefs'olidsolder in the body, said thermal cut-olf means when closed serv- *ing-tothermally disconnect the molten solder fromthc :solid solder.

4. A self-feeding soldering iron ofthe class described comprising: abody having an orifice throughlwhich'solid solder is adapted topass; atip having an orifice therein laligned with the orice in saidbody;.actuatable feeder V"n1eans for selectively feeding thesolidesolder` through `the orifice in the body into the Oriiice inthe-tip; means #in said tip for heating the same to a workingtemperature at which solder contained in the tip orifice is maintainediin ya molten state; and thermal cut-off means interposed lbetween thebody and the tip, saidzthermal cut-'oft means being resiliently movableto open. positionlby-.movement ,.ofisolid solder from the body ofthetip',said1cutoif means -resiliently moving to a closed positionuponzmelting of the solder in the tip for preventing conduction of heatfrom the molten solder in .theftiptothe solid solder in :the body.

5. A self-feeding soldering. Iiron-of '.the class described'.comprising: a body having an` orice through which solid ,solder isadapted to pass; a tip` haVillgJan oriiice 'therein Aaligned with theorice in said body; actuatable feeder v `means for selectively feedingthe solid solderthroughthe :orifice in the body into the oriceinthetip;.means in said tip for heating the same to a Working .temperature at,which solder contained in the tip vorifice vis maintained in amoltenstate', and thermal cut-oit means interposed between the body and thetip, said thermal cut-off means being of resilient material having arelatively low heat transfer coeiicient as comparedwith that of saidtip, -said cut-01T means having a fissure therein aligned Vwith theapertures in the body and tip, said fissure having a closed 1 positionat which the cut-off. meansthermally insulates vsolid solder in the bodyfrom molten solder in the tip,

said ssure being .resiliently enlargeable by solid-solderA for effectingits:passage`lfrom.thefbody into thetip through 'f the `cut-offmeansrupon actuationof, s'aid feed means, the Y resilient nature ofthematerialof thercut-oifmeans causling:V said iissure f to r'etumto;closednpositionupon` ,melting Aof thevsolidf solderzwithimthe cut-off:means.

6. fA self-feeding soldering .iron of Vthe, class described -comprisingra body having-an orifice: through which solid solder `isadaptedi-ftonpass;` axtiphavingan orifice therein aligned with theIorifice in'rsaid body; ,actuatable feeder -means for selectivelyfeedingtheisolid solder through the oriiice'in'1hev body into the:orifice in the tip; means in -said tip for .heating 'thea same-'toafworkingtemperature at which solder containediinthe tipV orifice ismaintained `in a moltentstategsand thermal cut-od means interposedbetween 'the body' and the tip,f:said thermal cut-off means beingofresilient materialthaving heat insulating properties, said cut-off meanshaving assurethereinaligned with the apertures inthe body and-tip, saidfissure having a closed position separating solid solder in the bodyfrom molten solderrin the=tipfwherebythe cut-off means Lprevents heat'vfrom-the tipv4 and-*molten `solder from causing melting vof-solidsolderinthe body, said fissure being resiliently enlargeable byrsolidsolder vfor eiecting its Vpassage from the body into thetip throughthe-iissure upon actuation-'of said='feedmeans,the*resilient nature ofthe material of `the cut-ofE-means causing said fissure to return toclosed position upon melting ofthe solder within the fissure.

7. A- se'lffeedingfsolderingiron ofthe yclass described comprising: abody having anior'ice through which-solid solderis adapte'dfto'pass;vatiphavingan orifice therein aligned with theoritieein saidlbody;actuatable feeder means forselectivelyfeedingthe'solidsolderthrough the orifice in thevbodyinto the orifice in the tip; means insaid tip for heating the Ysame to4 av working temperature at whichsolder contained-inthe-tp'orifice is maintained `in a molten state;` andthermal -cut otfrmeans interposed between the body andthe tip, saidthermal cut-otf means comprising a strip vofmateri'al having a rstposition separatingsolid solder-in the body 'from'molten solder in thetip,` and a*secondpositioninterconnecting the solid solder in'the`bodywith 'the-molten solder in the tip, said Kstrip being resilientlyurgedtow-ard said iirst position lwhen moved toward saidsecond position, saidstrip being contacted by solidsolderupon actuation `of said feedl'meansgand'movedto said-second position, said strip thereafter movingto saidiirst position upon melting of the solder in contact with -saidstrip.

8. A tip for a soldering iron" comprising a first elongated memberwith'faces at the axial ends thereof, said iirst member having'van axialoriiice therethrough and an axial slot connecting the'exterior of saidrst member vwith said orifice, and a 'second elongatedmember with facesat the, axial endsrthereof, 4said second member having an axial :orificetherethrough, said first member being engaged inv theoriiicen1said'second member, the axial orice inV said` iirst member beingVwettable by molten solder andthe axial4 oriiice in said second memberbeing non-wettable by molten solder.

9. A tip for a soldering iron, said tip being elongated with faces atthe. axial ends thereof, spaced surface means interconnecting said'faces, said surface meansdeiining .said faces, said ,surface meansAdefining a portion of an `aperture which extends between the faces, saidsurface means being wettable byimolten solder to form a conduitftherefor, said surface means being movable relative toeach other forchanging ,the size of the aperture, stop means for vlimitingV thecloseness `of the surface means,. and meansV for resiliently urging saidsurface means against said stop means.

Y 10. A tip in accordance with claim19y wherein said resilient meansVis. a helical V'spring vWound around said `tip, the ends of the springbeing adjacent said faces and :engaged between .the surface meansv forforming the stop means. Y

v 9 i 11. A tip for a soldering iron comprising rst means defining anorifice throughfwhch solder is adapted to pass, said first means havinga surface thereon wettable by molten solder, second means having asurface. thereon wettable by molten solder, rmeans mounting said firstand second means so that said surfaces are opposite and pass, said firstmeans having a surface thereon wettable by molten solder, second meanshaving a surface thereon wettable by molten solder, means mounting saidfirst and second means so that said surfaces are opposite and movablerelative to each other,dmeans to heat said first and second means to atemperature at which solid solder is reduced to amolten state, a workengaging surface on each of said first and second means connecting withits wettableisurface and means to selectively move said wettablesurfaces relative to each other for changing the spacing therebetween,the work engaging surfaces adapted to contact a soldered workpiece andmelt the solder thereon whereby the melted solder from the work-piece isdrawn between the wettable surfaces by capillary action, the spacing ofsaid wettable surfaces determining the amount of melted solder takenfrom Vthe work-piece.

13. A de-solderingtool comprising first surface means wettable by moltensolder, second surface means wettable f by molten solder, means mountingthe surface means for relative movement, said first and second meansadapted` to be heated to a working temperature at which solid solder incontact with the surface means would be reduced to a molten state, andmeansy to selectively vary the spacing between said first rand secondsurface means. f

14. A de-soldering tool comprising opposing surface t means vwhich arewettable by molten solder, said surface means being relatively movable:to vary the spacing therebetween, `and means to selectively vary thespacing so that molten solder can be drawn up between Ithe wettedsurface means by capillary action when the spacing is made small andmolten solder between the wetted surfaces can Y be removed therefromwhen the surfacermeans abut.

15. A self-feeding soldering iron of the class described comprising:a'body having an orifice through which solid solder is adapted to pass;a tip having an orifice therein aligned with theorifice in said'body;actuatable feeder 10 means for selectively feeding the solid solderthrough the orifice inthe body into the orice in the tip; means in saidtip for heating `the same to a working temperature at which soldercontained yin the .tip orifice maintained in a molten state; and thermalcut-off means interposed between the body and the tip, said thermalcut-off `means being responsive to melting of solder in the tip toAprevent the transfer of heat therefrom to solid solder in the body whensaid feeder means is deactuated for preventing heat from the moltensolder in the tip from melting the solid solder in the body.

16. A self-feeding soldering iron of the class described comprising: vabody having -an orifice through which solid solder is adapted toipass; atip having an orifice therein aligned with Vthe orifice in said body;actuatableifeeder.

means for selectively feeding the solid solder throughth orifice in thebody into the orifice in the tip; means in saidy tip for heating thesame to va working temperature at which solder contained in the tiporifice is maintained in a molten state; and means respons-ive todeactuation of saidl feeder when solder in the tip is molten tothermally disconnect thev latter from solid solder in the body forpreventing heatfrom the tip from melting the solid solder in the body.`l

- 17. A self-feeding-soldering iron of the class described comprising: abody having an orifice through which solid solder isadapted to pass; atip having an orifice therein aligned with the orifice in said body;actuatable feeder means for selectively feeding the solid solder throughthe orifice in the body into the orifice in -the tip; means in said tipfor heating the same to a working temperature at which solder containedin the tip orifice is maintained in a molten state;rand movable thermalcut-of means interposed between the body and the tip, said thermalcutoff means having an inoperative position for effecting heat transferfrom said tip to solid solder in the body and an operative position forpreventing heat transfer from said tip to solid solder in the body,means biasing said cut-off means toward operative position, actuation ofsaid feeder means causing movement of solid solder from said body towardsaid tip to maintain said thermal cut-off means at inoperative position,deactuation of said feeder means causing the means biasing said cut-olfmeans to move the same to operative position.

References Cited in the file of this patent 'Y UNITED STATES PATENTS872,229 Gifford Nov. 26,V 1907 1,449,517 A' Lame Mar. 27, 1923 1,457,508Dellman June 5, 1923 2,462,131 Rustin Feb. 22, 1949 2,780,712 ThomasFeb. 5, 1957 Nyborg Oct. 22, 1957

